#include<conio.h>
#include<stdio.h>
#include<math.h>
int main(){
	float s,a,b,c,p;
	printf("\nnhap vao a: ");
	scanf("%f",&a);
	printf("\nnhap vao b: ");
	scanf("%f",&b);
	printf("\nnhap vao c: ");
	scanf("%f",&c);
	p=(a+b+c)/2;
	s=sqrt(p*(p-a)*(p-b)*(p-c));
	printf("\ndien tich cua tam giac can tinh: s= %0.2f",s);
	getch();
}
